SignalQueue.h

// Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
// SPDX-License-Identifier: BSD-3-Clause-Clear
 
#ifndef SIGNAL_QUEUE_H
#define SIGNAL_QUEUE_H
 
#include "Utils.h"
#include "Signal.h"
#include "OrderedQueue.h"
#include "ExtFeaturesRegistry.h"
#include "ResourceRegistry.h"
#include "ServerInternal.h"
 
class SignalQueue : public OrderedQueue {
private:
    static std::shared_ptr<SignalQueue> mSignalQueueInstance;
    static std::mutex instanceProtectionLock;
 
    SignalQueue();
 
public:
    ~SignalQueue();
 
    void orderedQueueConsumerHook();
 
    static std::shared_ptr<SignalQueue> getInstance() {
        if(mSignalQueueInstance == nullptr) {
            instanceProtectionLock.lock();
            if(mSignalQueueInstance == nullptr) {
                try {
                    mSignalQueueInstance = std::shared_ptr<SignalQueue> (new SignalQueue());
                } catch(const std::bad_alloc& e) {
                    instanceProtectionLock.unlock();
                    return nullptr;
                }
            }
            instanceProtectionLock.unlock();
        }
        return mSignalQueueInstance;
    }
};
 
#endif